as exoteric are designed for the use of popular and ordinary readers.

10. Library books are such as are not usually perused, but kept for occasional reference and consultation: of this description are dictionaries, encyclopædias, &c.

11. Spiritual books treat expressly on the spiritual or Christian life, and its various exercises, as contemplation, prayer, &c.

The Romans also had books known by peculiar denominations; as the augural (libri augu. rales, by Cicero termed reconditi); those of the aruspices (libri aruspicini); the acherontic, also called libri Etrusci, from their supposed Etruscan origin; the fulgural (libri fulgurantes); the fatal, or books of destinies, which were consulted in all public calamities; and the Sibylline, those said to be composed by the Sibyls, and deposited in the Capitol. A copious account of these various books is given by Lomeier, in his treatise De Bibliothecis (cap. vi.), and by Pitiscus, in his Lexicon Romanarum Antiquitatum (vol. ii. pp. 84, et seq.); from whom most modern writers have transcribed their accounts.

SECTION II.

On the Forms and Sizes of Books-Different Styles of Book-binding.

A KNOWLEDGE of the forms of books is essential to the bibliographer, not only to enable him to arrange books in a library, or in a catalogue, but also to prevent confusion in describing editions. The form or size of a book depends upon the manner in which it is folded: thus a sheet folded into two leaves is a folio; into four, a quarto; into eight, an octavo, &c.; and each sheet is designated by a letter of the alphabet, placed in succession at the foot of the first page, and termed a signature; its use is, to distinguish the different sheets and pages, and consequently to facilitate the labour of the bookbinder. As, however, some of the smaller forms cannot be distinguished very readily, it becomes necessary to refer to the water-lines in the paper which indicate the size: but as books printed on vellum paper do not exhibit these water-marks, their size will best be ascertained by a careful attention to the signatures and pages, and also to the catch-words usually found at the right hand corner of each page'.

A printed sheet, when folded into two leaves,

On the origin and uses of signatures and catch-words, vide infra, chap. ii. sect. 1.

is called a folio, and contains four pages. A quarto sheet folded into four, contains eight

The water-lines in the sheets of paper are perpendicular in the folio, 8vo, 18mo, 32mo, 72mo, 96mo, and 128mo forms: in every other size they appear horizontally, except in 24mo, in which the water-lines are sometimes perpendicular, and sometimes horizontal. In order to ascertain its denomination correctly, the book should be opened between pages 48 and 49; if the catch-word be at the foot of page 48, and the signature at the bottom of page 49, the form is in 24mo; but if the catch-word is at the foot of page 64, and the signature at the bottom of page 65, the form is in 32mo. In some modern works, however, particularly the productions of the French press, catch-words are altogether omitted; and for the signatures

U

usually given, the number of the half-sheet or sheet is printed at the foot of the first page of each, in Arabic figures.

In general, most forms of books may be distinguished at sight, though mistakes are frequently made with regard to the size of the paper. Every book is either in large or small paper: in folios, there are different sizes, as elephant, imperial, atlas, super-royal, royal, crown, copy, demy and medium folios; quartos are imperial, royal, medium and demy: octavos are imperial, super-royal, royal, demy, medium, crown, foolscap, and copy;-duodecimos are royal, demy and medium; similar distinctions also exist with regard to the smaller sizes, which can only be ascertained by examination of the signatures. Thus, a small foolscap or copy octavo volume may easily be confounded with a duodecimo book, when placed on the same shelf; and a super-royal or imperial octavo, with a small quarto. These mistakes are not material in the arrangement of books upon shelves; but very important bibliographical errors would arise from them, if, in a catalogue, a small octavo were described as a duodecimo. Editions would thus be created, which never had any exist

ence.

In the infancy of printing, before the art became generally known, the books were made to

imitate in the most minute particulars, those which had preceded them from the hands of the scribes: hence they were printed on vellum, until that article became scarce through the multiplication of copies, when paper was manufactured to resemble vellum, and substituted in its place. The scribes prepared their parchment according to the sizes of the books which they wrote, which were mostly folios and quartos; few were octavo, and some were of a smaller size for children. Paper was made for books, the dimensions of which corresponded with those on parchment; the sizes of the books were chiefly folio and quarto, with some few octavos. Where any difficulty occurs in ascertaining the form of books on this sort of vellum paper, a very close inspection of the water-lines, which may sometimes be discovered, will help to determine the size of the volume. Folios, quartos and octavos may also be respectively distinguished by careful observation of the watermark, made by the paper-manufacturer in each sheet; if this be found in the middle of the sheet, the volume is in folio; if it appear at the bottom of the volume, it is in quarto; and if at the top of the sheet, it is in octavo.

Some Bibliographers have supposed that books were not printed in the octavo and smaller forms, earlier than 1480. M. Peignot, however, has